The 2560 can be streched quite a bit, provided your IC is doing the job.

THe difference between 300 and 260/270 is about one or two seconds worth of boost. The response of a 2560 is there everytime you move your big toe. Response can also be assisted by the exhaust manifold.

Once pushed 360 out of a 2560. Slightly insane for the street.

Does one have the driver experience and skill to handle wheel spin at 90 mph? I thought I did when 25, still can't believe I crashed so many times.

Because on the street you want the smallest turbo that will do the job, it makes the car more fun and you're not stressing it enough to worry about living on the upper end of the compressor efficiency chart.

Once a month is relatively frequent. I'd probably opt for a slightly larger gtx flavored iteration such as the one you've already mentioned.

Imagine that one of the cylinders of your motor could hold 100 big molecules when it is sitting still with a valve open. That would be equivalent to atmospheric pressure filling up the cylinder while it just sits there and does nothing.

Now, crank it up and let the cylinder try to suck air in while the piston goes down and the intake valve is open. The air must get through the air filter, but some gets lost in the process. Then the air must go through some tubes, around corners and past the throttle hanging out in the middle of everything.

All those things impede the flow a little bit and some molecules get left behind. Then the air must get through the intake manifold and past an intake valve that's jumping up and down and acting like St Peter trying to decide how many and who gets past the gate. Sadly, too few make the grade.

So, when the intake valve crashes shut and this combustion cycle is cast in stone, St Pete looks around and counts only 85 molecules in the chamber. That is 85% Evol.

Evol looses significance with the turbo, as it can grab off gobs of molecules and slam them into the system. Virtually as many as you want. Sometimes, more than the motor can tolerate. The Evol fakery here is easily shown by comparing acceleration at full throttle normally aspirated ( zero on the Vac/Boost gage) with holding part throttle with turbo to hold zero on the same gage. In my example, the power would be 15% greater because the turbo completely trounced the Evol and relagated it to meaninglessness.

The turbo can then be called the great master that threw the evil Evol down the pit into never never land.